More about Terri's Brain and Diagnosing PVS

First of all, let me point out that Kevin at Lean Left has exactly the right take on this. The medical issues are secondary, not central, to this case.

The legal issue in the Schiavo case has always been what Terri Schiavo wants, and the court’s rulings on withdrawal of her feeding tube have always been reflective of Terri Schiavo’s wishes, not her husband’s and not based on some sort of evaluation of whether her “life is worth living” or not. The Court has heard evidence from many people and has concluded that Terri’s wishes were known convincingly and that they were to the effect that she would not want to live in the condition she currently is in. […] The court’s various orders to terminate treatment have always been predicated on this wish of Terri Schiavo’s, not on the personal request of Michael Schiavo or on his, the court’s, or any other person’s evaluation of her “quality of life” or belief that her “life is not worth living.” The only person who, legally and morally, can make that determination is Terri Schiavo, and it is her previously-expressed determination in that respect that the court has acted on.

(Kevin, by the way, has been doing absolutely top-notch blogging on the legal and ethical issues of the Terri Schiavo controversy. If you don’t read Lean Left, you really should.)

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Nonetheless, I have a few links and comments to make regarding the debates over Terri’s diagnosis.

The National Review published an article which strongly implied that no responsible doctor could diagnose a Persistent Vegetative State (PVS) without an MRI and a PET scan.

Is that true? It seems to me that one way of answering that would be to look at what peer-reviewed medical journals say about diagnosing PVS.

For example, the British Medical Journal (1999) published an article entitled “The permanent vegetative state: practical guidance on diagnosis and management” which discusses diagnosis in great detail, yet never claims that MRIs, PETs, or any advanced imaging are necessary.

And the Royal College of Physicians published an article in Clinical Medicine (2003), “The vegetative state: guidance on diagnosis and management” pdf link). According to this article, either a CT or a MRI “often helps to clarify the cause of these clinical syndromes,” but did not say they were necessary for making a diagnosis. (Of course, Terri Schiavo has had both CTs and an MRI). As for more advanced scans, such as PETs, they specifically said “their use is not required for diagnosis of the VS.”

Note that both these articles come from Britain, where virtually no one had heard of Terri Schiavo before last month; it is therefore unlikely that these writers are in any biased by the current controversy. And although all of them are experts on diagnosing PVS – much more so than anyone the National Review quotes (none of whom, as far as I know, have published peer-reviewed articles on PVS diagnosis) – what they write clearly contradicts the NR‘s claims.

More importantly, the constant claim that further testing is required to be able to diagnose Terri Schiavo is simply unsupported by the objective medical literature.

(I’ve written more about the NR article here. I have to thank “Alas” reader “Bob,” who pointed out the Clinical Medicine article.)

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RangelMD, a doctor-blog, has a discussion of Terri’s condition. Referring to the image from Terri’s CT scan which has appeared on the web, Dr. Rangel writes:

To the medically trained person this scan appears grossly abnormal and sickening. The blue areas are remaining brain tissue but most of the scan shows black areas which are essentially fluid (cerebrospinal fluid). The normal body reaction to irreversibly damaged tissue is to replace it with fluid and this is clearly what has happened after Mrs. Schiavo suffered severe anoxic damage to her cerebral cortex . Most of what remains of her brain is essentially a fluid filled sac surrounded by a thin shell of brain tissue rather then the solid structure we normally associate with a brain. […]

While a CAT scan cannot detect brain function, further evaluation such as the use of a PET scan (Positron emission tomography) is not indicated. Advocates of further testing appear unaware of the paradox of calling for the evaluation of something (Mrs. Schiavo’s cerebral cortex) that is clearly not present on the CAT scan. A PET scan will not suddenly reveal a functional cerebral cortex in Mrs. Schiavo’s cranium as if it had been hiding behind her cerebellum all this time. Calling for a PET scan makes as much sense as calling for an X-ray of a leg that had been amputated. An MRI scan (magnetic resonance imaging) is not indicated either since the CAT scan is more than adequately sensitive enough to detect the presence or absence of a cerebral cortex.

Note that like the peer-reviewed articles, Dr. Rangel’s analysis undermines the premise of the National Review article, and of all those who have been saying that further testing is needed. The truth is, there is more than enough evidence; those who have not been convinced yet, will never be convinced by further testing. Terri Schiavo’s wishes have been ignored for well over a decade; to ignore them for even longer so that unneeded tests can be performed is not justified.